Twitter say they weren't hacked. If the accounts were compromised it was malware in the browsers.

That's true.

But generally speaking, somebody could get that amount of profile data with just one hacking..you wouldn't necessarily need to go and hack a load of computers, it could conceivably be done in one go, if you knew where the data was stored and could get onto the private network in the first place..that was the point I was making.

My account got hacked. I only made it to test a Twitter feed gadget for Wordpress. Had not logged in for a year, but the inactive Wordpress page still exists, so I'm pretty sure it was a glitch in Wordpress that got hacked..